U.S. Pat. No. 5,662,141 to Arosio issued Sep. 2, 1997 discloses a leak resistant fluid coupling arrangement whereby the female coupling half includes a tubular body shutoff upon which a male body and seal sit. See, FIG. 5 labeled “prior art” herein which is substantially similar to FIG. 3 of the '141 patent illustrating the male body 40 and seal 17′' residing adjacent and in engagement with the tubular body shutoff 7 of the female coupling half 2. FIG. 5 is a cross-sectional view 500 of a prior art female coupling half 2 and male coupling half 3 coupled. Reference numeral 4 indicates a hole or passageway for the communication of fluid therethrough. Reference numerals 18/19 signify a valve in the male coupling half 3 of the prior art as illustrated in FIG. 5.
Still referring to FIG. 5 herein, it will be noticed that the tubular body shutoff 7 includes an external stop (unnumbered) located longitudinally in the approximate middle thereof and it is this external stop which engages two springs identified with reference numerals 8 and 10 in FIG. 1 of the '141 patent. Reference numeral 8 is not shown in FIG. 5 herein. Spring 8 operates and acts between a fixed body and the external stop of the tubular body shutoff urging it longitudinally outwardly to shutoff against valve or bolt 5. Spring 10 operates and acts between the external stop and an annular sleeve 9 urging the sleeve longitudinally outwardly to create a flush face along with the flush face of the bolt or valve 5. Action of these two springs has the effect of floating the tubular body shutoff as spring 10 tends to urge the tubular body shutoff away from its closed position while spring 8 tends to urge the tubular body shutoff toward its closed position. Floating of the tubular body shutoff is not desirable because it promotes incomplete closure of the tubular body shutoff against the valve or bolt 5. If the tubular shutoff body 7 of the '141 patent does not move fully outwardly due to swelling of the seals in the device or because of tight tolerances between the parts and uneven expansion thereof, then the tubular shutoff body fails to close thus creating a leak from the female coupling half.
FIG. 4 is a quarter-sectional view 400 of a prior art female coupling half. FIG. 4A is a quarter-sectional view 400A of a prior art male coupling half. FIG. 4B is a quarter-sectional view 400B of a prior art female coupling half and male coupling half coupled. Referring to FIG. 4, a prior art coupling believed to be a product of Faster, SPA, of Italy is illustrated. It will be noted that reference numeral 490 indicates threads on the interior surface of the outer body thereof and the threads are located on both longitudinal sides of the unnumbered detents. This causes reciprocal threads 491 on the male coupling half as illustrated in FIG. 4A to traverse the unnumbered set of detents. Referring to FIGS. 4, 4A and 4B, reference numeral 407 refers to a tubular body shutoff which as stated above in connection with FIG. 5 is prone to hanging up (i.e., not going completely closed) due to the swelling of seal 451 and is not be expelled far enough toward the open end of the coupling half as designated generally by reference numeral 443 which is the flat face of valve or bolt 405. Spring 460 urges the tubular shutoff toward the open end. Spring 460A contributes to urging sleeve 409 toward the open end of the coupling but since sleeve 409 and tubular support 451 are not interlocked, spring 460A does not contribute to insuring that tubular shutoff 407 does in fact shut off.
Still referring to FIGS. 4, 4A, and 4B, reference numeral 414 represents a closed wall of a tubular bolt which is positioned by spring 422. Reference numeral 417 represents a seal which engages the tubular bolt of the male and the tubular body shutoff 407 when the device is coupled. Reference numeral 440 is a bolt body and reference numeral 419 is a shutoff surface and reference numeral 430 is seal. It will be noticed when reference is made to FIG. 4B that spring 460 urges tubular body shutoff 407 toward its closed position as illustrated in FIG. 4. However, the design of the prior art device does not include an interlock of the tubular body shutoff with the male coupling half to insure its closure.
Therefore, it is desirable to avoid leaks upon disconnection of a coupling by ensuring that valve in the female half of the coupling are interlocked with the male coupling half during disconnection of the coupling halves.